Democratic Sen. Barbara Boxer of California on Tuesday enlisted in the fight over military sexual assault with a sweeping proposal to change how the military prosecutes all major crimes.

Citing alleged problems in separate rape investigations involving the U.S. Naval Academy and Marine Corps Air Station Miramar in Southern California, Boxer introduced a bill that would limit the scope of certain pre-court-martial proceedings. She and her allies, who include some influential conservatives, say the changes will protect accusers from abusive questioning by defense attorneys.

“The current system is a disaster,” Boxer said Tuesday, “and the reason it’s a disaster is because there’s no protection for the victim in that room at all.”

Co-sponsored by 11 other lawmakers, including Sens. Lindsey Graham, R-S.C., and John McCain, R-Ariz., Boxer’s bill would exempt accusers from having to testify at the so-called Article 32 hearings, which occur before trial. The bill also would confine the hearings to determining whether there’s probable cause to charge suspects, and so forestall certain inquiries into the accusers.

“It’s catastrophic for the victims right now,” Boxer said, asserting that “it turns into a rampage against the victim.”

As evidence, she summarized news accounts about an eight-day Article 32 hearing that concerned the alleged rape of a female Naval Academy midshipman. According to reports, defense attorneys for three former Naval Academy football players aggressively questioned the woman over some 30 hours.

The Article 32 officer issued a 170-plus page report in September in which he recommended against prosecution and reportedly cast doubt on the woman’s credibility. Nonetheless, the superintendent of the Naval Academy decided to proceed with criminal charges against two of the former football players.

“The political pressure concerning sexual assaults in the military is relentless,” attorney Jason H. Ehrenberg, who represents one of the accused midshipmen, wrote in an Oct. 15 legal brief. “Any senior military official who is required to have Senate approval for advancement, such as the superintendent here . . . necessarily finds themselves in a political bind.”

Boxer’s proposal to restrain the Article 32 hearings goes beyond sexual assault to cover any significant case for which a general court-martial could be convened. The military holds several thousand such hearings each year, which sometimes have been likened to a grand jury proceeding.

It’s sexual assault, though, that’s motivating lawmakers to try rewriting military law in some very significant ways and with some potential consequences that may not yet be foreseeable.

As early as next week, the Senate will start considering a $625 billion defense-authorization bill that includes some changes to military law in response to widespread sexual assault allegations.

“The fact is, there are 26,000 sexual assaults a year,” Boxer said.

The commonly cited figure of 26,000 represents an extrapolation from a survey last year of about 1.5 percent of active-duty members of the U.S. military. The survey asked whether the service member had experienced “unwanted sexual contact,” which could range from “unwanted sexual touching” to intercourse.

The current version of the Senate defense-authorization bill requires that special counsel be assigned to sexual assault accusers and it restricts commanders’ ability to change court-martial results, among other changes.

Still ahead is a highly anticipated vote over an amendment authored by Sen. Kirsten Gillibrand, D-N.Y., and backed by Boxer that would remove sexual assault cases from the usual chain of command. The Pentagon opposes the proposal, as do key lawmakers, including Sen. Claire McCaskill, D-Mo., who, like Gillibrand, is a member of the Armed Services Committee

Military law experts and practitioners have raised cautionary flags about Congress making too many revisions in a complicated system.

“Dramatic changes to the Uniform Code of Military Justice . . . without careful study (and) consideration of impact, increase the likelihood of unintended consequences,” Brig. Gen. Richard Gross, legal counsel to the chairman of the Joint Chiefs of Staff, warned a Pentagon panel in September.

But one well-known military law expert, Eugene Fidell of Yale Law School, advised the panel that Article 32 proceedings impose “exorbitant” costs on defendants and taxpayers and need “reform,” a hearing transcript shows.